<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <script src="./vue.js"></script>
</head>
<body>
  <div id="app">
    <div ref="box">aaa</div>
    <p ref="op">ppp</p>
    <a href="" ref="aa">dwdw</a>
  </div>
  <script>
    let vm = new Vue({
      el:"#app",
      data:{
       
      },
      mounted(){
        console.log(this.$refs);
        this.$refs['box'].style.background="red";
        //document.querySelector("div").style.background="green"
      }
    })
  </script>
</body>
</html>